The extensive applications of MXenes, a novel type of layered materials known for their favorable characteristics, have sparked significant interest. This research focuses on investigating the impact of surface functionalization on the behavior of Mn2NX2 (X = O, F) MXenes monolayers using the "Density functional theory (DFT) based full-potential linearized augmented-plane-wave (FP-LAPW)" method. We observe and elucidate the variations in the physical properties of the Mn2NX2 by employing different surface terminations with F and O functional groups. We found that O-termination results in half-metallic behavior, whereas the N-termination evolves metallic characteristics within these MXene systems. Similarly, surface termination has effectively influenced their optical absorption efficiency. For instance, Mn2NO2 and Mn2NF2 effectively absorb UV light of magnitude 50.15×104 cm-1 and 37.71×104 cm-1, respectively. Additionally, they demonstrated prominent refraction and reflection characteristics, comprehensively discussed in the present work. Our predictions offer valuable perspectives into the optical and electronic characteristics of Mn2NX2-based MXenes, presenting the promising potential for implementing them in diverse optoelectronic devices.